Making concrete with coal!

Posted on 05 February 2016.

In the Czech Republic, Veolia recovers the fly ash produced when coal is burned. And what’s more, uses it to make substances for the cement and concrete industry.

Fly ash from coal combustion can be transformed into an excellent material for use in cement and concrete.

Coal fired power plants generate half of all the electricity used in the Czech Republic. This type of production results in the emission of fly ash - non-combustible fine particles that are driven out of the boiler in the flue gases during combustion. It includes substantial amounts of silicon dioxide (both amorphous and crystalline), aluminium oxide and calcium oxide. The good news is that these byproducts are largely recoverable. They can be used as a pozzolan: that is to say, combined with water, and in the presence of lime, the ash can be included in the composition of cements where they improve both the hydraulic qualities (the property of setting once mixed with water) and the texture. And into the bargain it means concrete with better resistance and durability! All with a sustainable development approach.

From ashes to roads

The substances made from recovered fly ash can be used in building and for roads in self-leveling products or road coatings. Veolia processes nearly 370,000 metric tonnes of byproducts from coal combustion in the Czech Republic. The Group helps the country to reduce the amount of waste for final disposal and so protects the environment. Recovering fly ash makes it possible to manufacture cement and concrete locally and to limit the carbon footprint resulting from the production of these materials. The virtuous circle continues over time, as concrete itself is recyclable and can be used as aggregate in new constructions.